An investigation into the links between island patterns and the mechanismsof thin film deposition

Statistical analysis of pictures of island arrays grown on a substrate duri ng thin-film deposition can yield useful information to the experimentalist such as the shape of the island size distribution. We present an investiga tion of how this type of information can in turn be used to identify the mo st important mechanisms governing the growth process. We have used a comput ational model based on deposition, diffusion, and aggregation (DDA) for the following situations: (1) normal DDA where the island size distributions s cale with coverage acid are distinguished by the critical island size; (2) DDA plus monomer evaporation, which yields scaling island size distribution s that lie between a powerlaw and the normal DDA results depending on the e vaporation rate; (3) DDA with a finite probability of islands absorbing mon omers, which yields similar distributions to case (2) but crucially does no t display the scaling with coverage; and (4) DDA with mobile islands where an even more dramatic departure from scaling is observed. (C) 2000 Elsevier Science B.V. All rights reserved.